The present invention relates to a method of manufacturing a device with micro-shutters and concerns more particularly a method of manufacturing a device including a plane support to which are fixed, by elastic attachments, miniature shutters capable of being controlled for rotation, as well as the application of such a method to obtain a light modulating device.
There has already been described in U.S. Pat. No. 4,383,255, entitled "Miniature display device", a display device with micro-shutters of the electrostatic type produced on a silicon wafer by means of techniques similar to those used for manufacturing integrated circuits. Although the use of a silicon support offers certain advantages among which is that of allowing the application of known and well practiced working techniques, it entails, however, certain constraints or limitations which are due to the material itself. Thus, the crystallographic orientations of monocrystalline silicon impose well defined planes of chemical attack; this limits, among other things, the possible geometries. For further information, reference may be made to the article by Kenneth E. Bean entitled "Anisotropic etching of silicon", published in the journal IEEE Transactions on Electronic Devices, Vol. ED-25, No. 10, of October, 1978. Furthermore, the silicon wafers actually available on the market have a maximum given diameter; this proportionately limits the size of the display device that can be produced. On the other hand, when the thickness of the wafer must be reduced to values of about 200 .mu.m, the mechanical fragility thereof is such that very great precautions in handling are required.
An object of the invention is therefore to provide a method of manufacturing a device with micro-shutters involving materials which do not present the above-mentioned disadvantages.
Another object of the invention is to provide a method of manufacturing a device with micro-shutters based on the use of relatively cheap materials and involving photolithographic operations similar to those used in the manufacture of integrated circuits.
Another object of the invention is the application of the method referred to hereinbefore to obtain a light modulating device.
Another object of the invention is the application of the method referred to hereinbefore to obtain a display device.